His clinical and research interests include anaerobic bacteria and their infections such as C. difficile infections (epidemiology, prevention and therapy), human and animal bite wounds (bacteriology, clinical presentations, complications and therapy); bacteriology and therapy of intra-abdominal infections, diabetic foot infections; in vitro susceptibility of fastidious and anaerobic bacteria to new antimicrobial agents; and pharmacokinetics and pharmacodynamics of new agents. He has over 400 publications including in the New England Journal of Medicine, Science, JAMA, PLOS, Lancet ID and Clinical Infectious Diseases.